Title:
EVALUATION AND MOLECULAR CHARACTERIZATION OF A NATIVE BEAUVERIA BASSIANA ISOLATE FOR THE BIOLOGICAL CONTROL OF RHIPICEPHALUS MICROPLUS IN TROPICAL CATTLE PRODUCTION

Authors:
Adara Patricia Molar Guerrero, Armando Arrieta-González, Karla Lissette Silva-Martínez and Erika Andrea Hernández

Abstract:
Rhipicephalus microplus is a tick of major veterinary relevance that causes significant economic losses in tropical cattle production due to its blood-feeding behavior and its role as a vector of hemoparasites. The extensive use of chemical acaricides has led to the development of resistant tick populations, highlighting the need for sustainable biological alternatives. Among these, entomopathogenic fungi such as Beauveria bassiana have gained attention for their efficacy against arthropod pests and low environmental impact. This study aimed to evaluate the in vitro and in situ efficacy of a native B. bassiana isolate against engorged females of R. microplus and to confirm its taxonomic identity through multilocus phylogenetic analysis. Two treatments were applied by immersing ticks in 5 mL and 10 mL of a conidial suspension (1?×?10? conidia/mL), along with an untreated control group. Fungal infection was assessed based on the presence of external mycelial growth on tick cadavers. DNA was extracted from the fungal isolate, and the ITS, RPB1, and TEF1-? regions were amplified and sequenced. Phylogenetic analyses using Bayesian inference and maximum likelihood confirmed the identity of the isolate as B. bassiana, showing high similarity to known type strains. The treatments resulted in infection rates of 64.1% (5 mL) and 71.8% (10 mL), while no infection was observed in the control group. These findings demonstrate the potential of this native B. bassiana isolate as a biological control agent against R. microplus and support its integration into sustainable pest management strategies in tropical livestock systems.

Keywords:
Rhipicephalus microplus, Beauveria bassiana, biological control, phylogenetic analysis.

DOI:
https://doi.org/10.37500/IJESSR.2025.8419

Date of Publication: 16-08-2025